Dismantling of Printed Circuit Boards Enabling Electronic Components Sorting and Their Subsequent Treatment Open Improved Elemental Sustainability Opportunities
Résumé
This critical review focuses on advanced recycling strategies to enable or increase recovery
of chemical elements present in waste printed circuit boards (WPCBs). Conventional recycling
involves manual removal of high value electronic components (ECs), followed by raw crushing of
WPCBs, to recover main elements (by weight or value). All other elements remain unrecovered and
end up highly diluted in post-processing wastes or ashes. To retrieve these elements, it is necessary to
enrich the waste streams, which requires a change of paradigm in WPCB treatment: the disassembly
of WPCBs combined with the sorting of ECs. This allows ECs to be separated by composition and
to drastically increase chemical element concentration, thus making their recovery economically
viable. In this report, we critically review state-of-the-art processes that dismantle and sort ECs,
including some unpublished foresight from our laboratory work, which could be implemented in a
recycling plant. We then identify research, business opportunities and associated advanced retrieval
methods for those elements that can therefore be recovered, such as refractory metals (Ta, Nb, W,
Mo), gallium, or lanthanides, or those, such as the platinum group elements, that can be recovered in
a more environmentally friendly way than pyrometallurgy. The recovery methods can be directly
tuned and adapted to the corresponding stream.
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